Cahill and Marling are self-described space geeks who met in college at Georgetown. They collaborated on short films, but often spent time just shooting the breeze, making up stories they’d build around space factoids.

They became fascinated with the idea of another earth, Earth 2, and the implications of speaking with the person who would have the greatest empathy with you – yourself.

“From there we worked our way backwards into what is the human drama where meeting yourself with the possibility of confrontation would have the greatest emotional resonance?” Marling said. “And that seemed to be a story a girl who couldn’t forgive herself for something she had done.”

They wrote the story of Rhoda Williams, a young woman who on the eve of going to MIT to study astrophysics hears scientists have discovered Earth 2. That night she also makes a terrible mistake that not only wrecks her life, it destroys a stranger’s family.

You can hear the rest of their conversation, including one 12-year-old’s rave review, by clicking on the audio link below: